The "Trinder reaction", named after its discoverer, is a reaction for detecting hydrogen peroxide evolved in a solution, by producing a colored compound. The colored compound which develops can then be determined spectrophotometrically.
Color development by hydrogen peroxide is obtained if a peroxidase enzyme, phenylpyrazone derivative and a compound of phenolic or aromatic amine structure are present in the solution. It should be noted that the expression "Trinder reaction" has a wider meaning herein than the reaction originally conceived by Trinder (A., Clin. Biochem., 6, 24, 1969) in which a peroxidase, 4-aminoantipyrine and phenol were used.
The Trinder reaction, when taken in its stated wider sense, is commonly used as an indicator reaction in clinical chemistry for determining numerous substrates, including uric acid, cholesterol, glucose, triglycerides etc. For example:
reagent uric acid: Uricase.fwdarw.H.sub.2 O.sub.2 .fwdarw.Trinder PA1 reagent cholesterol: Cholesterol Oxidase.fwdarw.H.sub.2 O.sub.2 .fwdarw.Trinder PA1 a) a phenylpyrazone derivative, PA1 b) a phenol or an aromatic amine, PA1 c) a peroxide enzyme, PA1 d) aqueous buffer, and PA1 e) a polyalkylaminepolyacetic acid or a salt thereof chelating agent as stabilizer. PA1 1) N,N-dialkylaniline compounds, PA1 2) N,N-dialkyl-m-toluidine compounds PA1 3) toluidine and aniline sulphopropyl derivatives, PA1 4) N-ethyl-N-(3-sulphopropyl)-m-anisidine and PA1 5) N-ethyl-N-(2-hydroxyethyl)-m-toluidine.
One of the biggest problems in the use of this reaction is the spontaneous aspecific coloration which occurs with time and which is accelerated by particular conditions such as storage at temperatures exceeding refrigerator temperatures or exposure to light.
This increase in coloration has been a serious obstacle in the use of Trinder reagents after a certain period of time because it reduces the photometric linearity range or the wavelength used in determining the coloration.
The availability of a preparation containing the Trinder reaction reagents with which the aforesaid drawbacks are absent is therefore of obvious importance.